public class Operate {
    public static void main(String[] args) {
        int i = 10;
        i += 4;
        System.out.println(i);
        byte b = 10;
        b += 4;
        System.out.println(b);
        byte d = 4;
//        d = d + 4;//err
        d = (byte) (d + 4);
        System.out.println(d);
    }
}
